Continuous hemofiltration in pigs with hyperdynamic septic shock affects cardiac repolarization.
OBJECTIVE
Sepsis has been defined as the systemic host response to infection with an overwhelming systemic production of both proinflammatory and anti-inflammatory mediators. Continuous hemofiltration has been suggested as possible therapeutic option that may remove the inflammatory mediators. However, hemodialysis and hemofiltration were reported to influence cardiac electrophysiologic parameters and to increase the arrhythmogenic risk. We hypothesize that sepsis affects electrophysiologic properties of the pig heart and that the effects of sepsis are modified by hemofiltration.


METHODS
Laboratory animal experiments.


METHODS
Animal research laboratory at university medical school.


METHODS
Forty domestic pigs of either gender.


METHODS
In anesthetized, mechanically ventilated, and instrumented pigs sepsis was induced by fecal peritonitis and continued for 22 hours. Conventional or high-volume hemofiltration was applied for the last 10 hours of this period.


RESULTS
Electrocardiogram was recorded before and 22 hours after induction of peritonitis. RR, QT, and QTc intervals were significantly shortened by sepsis. The plasma levels of interleukin-6 and tumor necrosis factor-alpha were increased in sepsis. High-volume hemofiltration blunted the sepsis-induced increase in tumor necrosis factor-alpha. Action potentials were recorded in isolated ventricular tissues obtained at the end of in vivo experiments. Action potential durations were significantly shortened in septic preparations at all stimulation cycle lengths tested. Both conventional and high-volume hemofiltrations lead to further shortening of action potential durations measured afterward in vitro. This action potential duration shortening was reversed by septic hemofiltrates obtained previously by conventional or high-volume hemofiltration. Tumor necrosis factor-alpha (500 ng/L) had no effect on action potential durations in vitro.


CONCLUSIONS
In a clinically relevant porcine model of hyperdynamic septic shock, both sepsis and continuous hemofiltration shortened duration of cardiac repolarization. The continuous hemofiltration was not associated with an increased prevalence of ventricular arrhythmias. Tumor necrosis factor-alpha or interleukin-6 did not contribute to the observed changes in action potential durations.
Stengl
Milan
M
Department of Physiology, Charles University in Prague, Faculty of Medicine and Teaching Hospital in Plzen, Plzen, Czech Republic. milan.stengl@lfp.cuni.cz
Sykora
Roman
R
Krouzecky
Ales
A
Chvojka
Jiri
J
Novak
Ivan
I
Varnerova
Veronika
V
Kuncova
Jitka
J
Nalos
Lukas
L
Sviglerova
Jitka
J
Matejovic
Martin
M
D000200:Action Potentials; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000503:physiopathology / Q000517:prevention & control; D004195:Disease Models, Animal; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006439:Hemodynamics; D006440:Hemofiltration; D015850:Interleukin-6 / Q000096:biosynthesis; D008297:Male; D012121:Respiration, Artificial; D012772:Shock, Septic / Q000378:metabolism / Q000503:physiopathology* / Q000628:therapy*; D034421:Sus scrofa; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D016276:Ventricular Function
D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha